1. Field of the Invention
This invention relates to an optical device for the use in display devices, light modulator devices, etc., and particalarly to a novel optical device utilizing the swelling and shrinking of gel under action of an electric field.
2. Description of the Prior Art
Non-luminous display devices have been regarded as important because they can produce natural color tone and do not cause any fatigue to human eyes, and they include, for example, electrochromic display devices (ECD), liquid crystal display devices (LCD), etc. However, their quality and performance are not satisfactory. For example, ECD is as low in display contrast that it is hardly observable in a dim place and discrimination of fine image is hard at a distance.
On the other hand, LCD has such another disadvantage as a restricted angle of visual field, besides the above noted disadvantages.
Similar problems exist even when they are used in the light modulator devices such as light shutters, etc.